PHENOTYPIC CHANGES IN CULTURED HAMSTER EMBRYONIC LIVER CELLS AS STUDIED BY IMMUNOFLUORESCENCE

Dedifferentiation of cultured hamster embryo liver cells with respect to the liver-specific antigen (LSA) was studied by means of the immunofluorescent technique. Depending on the intercellular relations, conditioned by the method used for culture, liver cells may either preserve or lose LSA. LSA disappeared from the cells after they were grown in monolayer cultures for a few days. Conversion of the cells from LSA plus to minus was due to phenotypic changes and not to selection. Various factors restricting division of the cells in monolayer cultures affected unequally their capacity to synthesize LSA. LSA was preserved in cells maintained at 24°C, but disappeared from those in which division was stopped by X-irradiation. Contact among like cells prevents the disappearance of LSA, and its synthesis may be restored in organ-cultured pellets of cells which have been precultured in monolayers for no longer than 5-6 days. © 1968.